package com.lwz.vueblog.shiro;

import cn.hutool.json.JSONUtil;
import com.lwz.vueblog.common.lang.Result;
import com.lwz.vueblog.util.JwtUtils;
import io.jsonwebtoken.Claims;
import org.apache.shiro.authc.AuthenticationException;
import org.apache.shiro.authc.AuthenticationToken;
import org.apache.shiro.authc.ExpiredCredentialsException;
import org.apache.shiro.web.filter.authc.AuthenticatingFilter;
import org.apache.shiro.web.util.WebUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.util.StringUtils;
import org.springframework.web.bind.annotation.RequestMethod;

import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;


/**
 * @author Lw中
 * @date 2020/6/20 11:31
 */

@Component
public class JwtFilter extends AuthenticatingFilter {

  @Autowired
  JwtUtils jwtUtils;

  @Override
  protected AuthenticationToken createToken(ServletRequest servletRequest, ServletResponse servletResponse) throws Exception {

    HttpServletRequest request = (HttpServletRequest) servletRequest;
    String jwt = request.getHeader("Authorization");
    if (StringUtils.isEmpty(jwt)) {
      return null;
    }
    return new JwtToken(jwt);
  }

  /**
   * 拦截校验
   */
  @Override
  protected boolean onAccessDenied(ServletRequest servletRequest, ServletResponse servletResponse) throws Exception {

    HttpServletRequest request = (HttpServletRequest) servletRequest;
    String jwt = request.getHeader("Authorization");
    if (StringUtils.isEmpty(jwt)) {
      return true;
    } else {
      // 校验jwt
      Claims claim = jwtUtils.getClaimByToken(jwt);
      if (claim == null || jwtUtils.isTokenExpired(claim.getExpiration())) {
        throw new ExpiredCredentialsException("token已失效，请重新登录");
      }
      // 执行登录
      return executeLogin(servletRequest, servletResponse);
    }
  }

  @Override
  protected boolean onLoginFailure(AuthenticationToken token, AuthenticationException e, ServletRequest request, ServletResponse response) {

    HttpServletResponse httpServletResponse = (HttpServletResponse) response;

    Throwable throwable = e.getCause() == null ? e : e.getCause();
    Result result = Result.fail(throwable.getMessage());
    String json = JSONUtil.toJsonStr(result);

    try {
      httpServletResponse.getWriter().print(json);
    } catch (IOException ioException) {

    }
    return false;
  }

  @Override
  protected boolean preHandle(ServletRequest request, ServletResponse response) throws Exception {

    HttpServletRequest httpServletRequest = WebUtils.toHttp(request);
    HttpServletResponse httpServletResponse = WebUtils.toHttp(response);
    httpServletResponse.setHeader("Access-control-Allow-Origin", httpServletRequest.getHeader("Origin"));
    httpServletResponse.setHeader("Access-Control-Allow-Methods", "GET,POST,OPTIONS,PUT,DELETE");
    httpServletResponse.setHeader("Access-Control-Allow-Headers", httpServletRequest.getHeader("Access-Control-Request-Headers"));
    // 跨域时会首先发送一个OPTIONS请求，这里我们给OPTIONS请求直接返回正常状态
    if (httpServletRequest.getMethod().equals(RequestMethod.OPTIONS.name())) {
      httpServletResponse.setStatus(org.springframework.http.HttpStatus.OK.value());
      return false;
    }

    return super.preHandle(request, response);
  }
}
